doc: Document mumi am, compose and www subcommands.

* doc/contributing.texi (Debbugs User Interfaces)[Command-line interface]:
Document mumi am, compose and www subcommands.
* doc/guix.texi: Bump copyright year.

Change-Id: I28bde9454ad35115ed60fe4d6ffa35fad599b2d1

doc/contributing.texi

@@ -2395,9 +2395,9 @@ To view discussions related to issue number @var{n}, go to
 @subsubsection Command-line interface
 
 Mumi also comes with a command-line interface that can be used to search
-existing issues, open new issues and send patches.  You do not need to
-use Emacs to use the mumi command-line client.  You interact with it
-only on the command-line.
+existing issues, open new issues, compose replies, apply and send
+patches.  You do not need to use Emacs to use the mumi command-line
+client.  You interact with it only on the command-line.
 
 To use the mumi command-line interface, navigate to a local clone of the
 Guix git repository, and drop into a shell with mumi, git and
@@ -2434,8 +2434,61 @@ Pick an issue and make it the "current" issue.
 opened on 24 Jan 09:42 Z by Efraim Flashner
 @end example
 
-Once an issue is the current issue, you can easily create and send
-patches to it using
+Once an issue is the current issue, you can open the issue in a web
+browser, compose replies, apply patches, send patches, etc. with short
+succinct commands.
+
+Open the issue in your web browser using
+
+@example
+~/guix [env]$ mumi www
+@end example
+
+Compose a reply using
+
+@example
+~/guix [env]$ mumi compose
+@end example
+
+Compose a reply and close the issue using
+
+@example
+~/guix [env]$ mumi compose --close
+@end example
+
+@command{mumi compose} opens your mail client by passing @samp{mailto:}
+URIs to @command{xdg-open}.  So, you need to have @command{xdg-open} set
+up to open your mail client correctly.
+
+Apply the latest patchset from the issue using
+
+@example
+~/guix [env]$ mumi am
+@end example
+
+You may also apply a patchset of a specific version (say, v3) using
+
+@example
+~/guix [env]$ mumi am v3
+@end example
+
+Or, you may apply a patch from a specific e-mail message.  For example,
+to apply the patch from the 4th message (message index starts from 0),
+run
+
+@example
+~/guix [env]$ mumi am @@4
+@end example
+
+@command{mumi am} is a wrapper around @command{git am}.  You can pass
+@command{git am} arguments to it after a @samp{--}.  For example, to add
+a Signed-off-by trailer, run
+
+@example
+~/guix [env]$ mumi am -- -s
+@end example
+
+Create and send patches to the issue using
 
 @example
 ~/guix [env]$ git format-patch origin/master
@@ -2452,11 +2505,8 @@ To open a new issue, run
 ~/guix [env]$ mumi new
 @end example
 
-and send patches
-
-@example
-~/guix [env]$ mumi send-email foo.patch bar.patch
-@end example
+and send an email (using @command{mumi compose}) or patches (using
+@command{mumi send-email}).
 
 @command{mumi send-email} is really a wrapper around @command{git
 send-email} that automates away all the nitty-gritty of sending patches.

doc/guix.texi

@@ -53,7 +53,7 @@ Copyright @copyright{} 2017, 2019, 2020, 2021, 2022, 2023 Maxim Cournoyer@*
 Copyright @copyright{} 2017–2022 Tobias Geerinckx-Rice@*
 Copyright @copyright{} 2017 George Clemmer@*
 Copyright @copyright{} 2017 Andy Wingo@*
-Copyright @copyright{} 2017, 2018, 2019, 2020, 2023 Arun Isaac@*
+Copyright @copyright{} 2017, 2018, 2019, 2020, 2023, 2024 Arun Isaac@*
 Copyright @copyright{} 2017 nee@*
 Copyright @copyright{} 2018 Rutger Helling@*
 Copyright @copyright{} 2018, 2021, 2023 Oleg Pykhalov@*